This invention relates generally to switching systems and particularly to switching systems having utility in accessing telephone circuits from any of several testing locations.
It is a general practice to individually access special service telephone circuits in order to make tests upon the quality of the circuits. It has been a standard practice in the telephone industry to connect each of the special service telephone circuits to its own individual set of test jacks at a test board location in order to obtain test access. This requires a substantial amount of space for very large test boards to hold all of the thousands of jacks and involves a great deal of wiring since each of the telephone circuits to be tested must be brought individually to each test board.
More recently, other systems have been introduced wherein a few sets of test jacks are utilized to access a large number of telephone circuits my means of a dial initiated switching circuit. That is, a switching circuit at the location of the telephone circuits is commanded by a dialed signal from a test panel a distance therefrom to connect a particular one or more telephone circuits to the test panel jacks for testing. An existing system of this type is a Bell System SMAS (Switching Maintenace Access System). However, such access systems are still bulky and require a great deal of wiring.
Therefore, it is a principal object of the present invention to provide a switched access system particularly adapted for selectively accessing a large number of telephone circuits and that requires even less wiring between a test position and the telephone circuits, less bulk of equipment and space requirements than existing systems and one that is extremely reliable in operation.
It is another object of the present invention to provide such a switching system that is easily expandable in capacity so that unnecessary capacity does not need to be prematurely installed before it is needed.
It is a further object of the present invention to provide a switching system where a plurality of test ports can be located within a telephone switching office at various locations therein a distance from each other and a distance from the telephone circuit access points.
It is also an object of the present invention to provide a telephone switching access system that is easily compatible with additional remote measuring equipment.